Driving key and process of fitting the same



Dec. 26, 1922. 1,439,769

Y R. A. SMITH. DRIVING KEY AND PRocEss oF FITTING THE SAME.

FILED .JULY 6, 1922.

64 J2 0^. a? 1NI/ ToIg. if@ fg?, J7 j y@ 0/56 56 /53 sofr c I BY ATTORNEY.

unite rer criss.

nonnivr ii. siiirii, or inaiiwaii, New JERSEY. iissien'on To siiii'riiasiinnniii., or MAHWAH, ivnw innsnr, A corairrivniisiiir consis'rineorsein ROBERT A.

SMITH- AND JOHN J. SERRELL.

DRIVING KEY AND JPRCESS OF FITTING THE SAME;

iippiicetion ined iuiy e, i922. semi Nq. 573,195.

To all liv/"mm z'mcn/ concern:

Be it known that LRonrirr A. SMi'rHya citizen of the United States, andresident of Mahwah, Bergen County, State of New Jer,- sey, have `made acertain new and useful Invention Relating .to Driving` Keys andProcesses of Fitting theSanie, ot which the following is aspecilication, taken in connection with the accompanying drawing, whichforms part of the same.

This applicationisa continuation in part of iny copending applicationSer. No. 484,094 filed July l2, 1921that is, this case contains subjectmatter taken therefrom. f f y This inventionrelates especially todriving keysand `processes of ltting thesanie .for coupling shafts toother parts off niachinery, the keys being provided with cut- .asomewhat diagrammatic way a number of ,illustrativekeys for usein suchprocesses:

l isa ksectional view showing the inse that when the key is forciblydriven into the usual rough key wayin the shaft and other cooperatingparts these cutting edges cut or finish one or more of thel innersurfaces of the vkey way to .such an extent that the corresponding faceof the key is torcedor wedged against the saine to give a wedgingcloselyiitting and secure driving connection between the parts. Especiallywhere the key is to be withdrawn at relatively frequent intervals'it ispreferably thoroughly greased or oiled adjacent the cutting faces beforeit is drivenr whichfpi'events oritiinimixes the ahrasionior undesirablecutting action which might otherwise occur between these stronglyengaging inetal inccs.` it is usually desirableto-Aiorin such keys othardened and tempered steel at least adjacent the head or forwardcutting portion which may be advantageously ground to size after suchheat treatment or other isc accurately shaped so as to 'forni thecutting or portions lwhich preferably have adjacent chip retainingrecesses especially where several cutting edges are formed on the` sainetace ott the key so that each cutting- "edge can successively Afinish orcut oli portions ot the key way 'face to more accurately iinish `thesaine. lt is also advantageous'to guide or align the head oi the keywhile yit is heing driven and for this purpose a somewhat narrowerorsma'ller forward guiding align- `ing portion may bey formed ahead ofthe main cutting edges or portions so that the Lkey is automaticallyyguided or aligned as it is hammered or forced into the key way. Itisalsodesirable in inanyrcases to adjust the` effective length of the key bycutting )oit or removing partsofthesame before 4oi' after it is driveninto place and for this purpose a severable reark or driving4 end may beformed on the key end of relatively sott material which may be cut ofi'by hack saws.

letc.,l or by having a hard driving end formed with breaking nicks ornotches en tending more or less yaround vit at the desired intervals sothat portions may bev broken oii'f eitherbefore or after the key isdriven.

In theaccompanying 'drawing showing in of suoli' .a key; and '1 Fig; 2is an endview thereof. Fig. 3 is an enlarged topi view' greater detailand other illustrative forins of keys.

partly in section showing the pkey construction in F ig. 7 is a sideview showing anotlieriorin i i of key and n Fig. 8 is a correspondingend view.

Fig; 9 is a sidev view showing still another illustrative construction,and y AFig.V l0 is an end view thereof. f As indicated in Figs. l and2,*the ordinary `rough slotted or milled keyways 11, i4 may be' formedin any. desired'way in the cooperating part'ssuch asthefshai't l2 andthe flange andrcou'plingY nieinberl for example. .The self-fitting orcutting key -l which may have oiie or more cutting edges such as 2, onat least one of the driving "faces oi the Ain'en'ibe'is uiider serviceconditions; and it desired, both of these opposite driving facesciittinge`olg`g'es'-` 2., 3 softhat when the key is forced in'tolthisslightly under-sized keyway,

these edgesai'itoinatically cut their own slot of such size as toaccurately accommodate. or

'it 'the body@ of 'the key. coiirse'the'end l kev such as its'u er orlower notched edges v Y C i `iiiay be formedw'ith `one or more of such10 oi the key may vbe beveled if desired so to be driven home byu hammeror other means. lt is also desirable to form such self-fitting cuttingkeys of tool steelwor still better of special tough strong steel, whichis heat treated to harden and toughen the bodyI of the key and leave thecutting edges in most effective condition. In many cases it is desirableto preliminarily or roughly form these cutting edges and then afterhardening and tempering the key, to grind or otherwise finish orstraighten the key body, and in some cases to grind the cutting edges inproper relation thereto to get best results.

As is indicated in Fig. 3 one or more cutting edges such as 2, 3 may inymany cases be `advantageously formed on both of 'the opposing drivingfaces of the key, and each of these successively acting cutting edgesmay be slightly larger so that each of them may remove a few thousandthsof an inch from the corresponding face or edge of the keyway as the key'is driven home. It is sometimes advantageous to have the final cuttingedge such as 3 formed so as to take only a light out, this materialbeing accommodated in a chip retainer recesssuch as 6 formed adjacentthis cutting edge and eX- tending inward, so as to give ample room toproduce the desired cutting angle for this edge. In some cases also oneor morecutting edges such as 5 may be formed on one or both of the otherfaces of the key besides the driving faces thereof, although it isusually better to have at least one of these inner and outer key facesflat sopas to act somewhat `more efficiently as a guide and aligningsurface when the key is inserted. ln some cases also the key body mayhave a wedging action if the inal cutting edge is slightly smaller thanthe adjacent driving face of the key, and as shown on an exaggeratedscale in Fig. 3 the width of the portionsy 8 of the key adjacent theVcutting edges 3 may be slightly smaller y.than

.the corresponding driving faces 9; and the inclined. or curved portion7 `joining these' tivo faces may have a few thousandths of an inch or`less difference so as tose'cure the desired tightness of drive itdepending of coursefon the size of key employed.

Fig. 4 shows another illustrative key 21 'which may have the opposingdriving faces l'oiined with cutting edges 1.9 adjacent the front end orhead of the key; and in some enses also a forward aligning guidingportion 18 having somewhat rounded or drilled edges of slightly lesswidth may be forined ahead of these lateral cutting edges so as to guidethe key when inserted and-during its first cutting movements. Thisguiding portion may be formed in some cases with forward cutting edges17 if desired, and lintermediate cutting edges v16 may be formed konthis guiding portion `preferably on the uplaagjes per face thereof, Theupper face ofi the key proper may also be .formed with a cutting edge 20preferably longitudinally displaced from the lateral cutting edges 19and these cutting edges may advantageously be formed with cuttingvanglesof about 750 as is indicated in connection with the cutting edges 19.Suitable chip retaining recesses such as 23 may be formedadjacent any orall of these cutting` edges. It is in many cases desirable to have thelength of these selffitting keys adjustable so that any suitable 4lengthcan be cut or broken oft' from the standard length keys manufactured andsold; and for this purpose it is often advantageous to form angularbreaking notches or nicks such as 22 extending more or less completelyaround the key at intervals of a quarter or afhalf inch apart adjacentits rear driving end where it is struck by the hammer driving the keyinto the keyway. Such weakening breaking nicks or angular recesses ornotches make it possible to break oit one or more sections from the keybefore or after it is started into the keyway; and the key may, forinstance,'be placed in a heavy vise with the desired amount project-ling beyond'one of these weakening nicks or notches and then by strikingthe projecting end laterally with a heavy hammer it 'can loe broken oitand the remaining end portion i ground or otherwise smoothed up beforedriving the key home.

i Fig. 5 shows another illustrative arrangement for making the keylength adjustable and as there'shown, the self-fitting key may y `have ahardenedhead 32 comprising the cutting edges or portions andthe guidingaligning portions of the key, while the opposite or reardriving end S3of the key is left in soft or annealed condition so that more or less ofthis end can be cut off by hack saws or otherwise removed before the keyis driven into the keyway, and of course, if desired, a beveledportion'such as 34 may be formed to prevent undesirable spreading of theextreme driving' end of this key where the upsetting forces are usuallylarge. Such keys may have any suitable arrangement of cutting edges and,as indicated, the hardened head 3201i the keymay be provided with thecutting edges 39 on its opposite lateral or driving faces, any suitablechip .recesses such. as 4-0 being ground or otherwise formed :id-

Qacent` these edv'es. In this case the u wer a l cutting edge 38 isshown as being formed with the bottomk of the keyway inthe shaft whichis usually fairly straight on this-lower milled surface-thusprevcntingor minimizing subsequent twisting or bendingj off the keyduring itsfdriving whichis ofcourse un desirable. formed with a-somewhatreduced forward aligning guiding portion having. thezlateral faces 37and the uppeiyfacefwhich may be formed with sharp cuttingI edges such as35, if desired. y, y y

Fig. 6 shows'another illustrative self-litting key 24 which-may vhaveanumber of cutting edges 27, 28- and 29 ononefor both of the drivingfaces 30, and-also if desired such cutting edges as may be formed on oneof the other faces of the key at right angles to thesedriv-ing faces.yThese-cutting edgesare of course progressively large r. so that eachcutting edge removes part of the materiales the'key is driven forward,and this is of course advantageousy since rthecutting edges are lesslikely to vbebroken or. injured as the key is driven home. ln some casesit isdesirable to form the leading cuttingfedge with a substantiallyparallel guiding or aligning face or. member .26 adjacenttlie same,which somewhat promotesy the desired lateral positioning ofthe key asit.Y `driven into the rough keyway. @f course by` having different oroversized lself-fitting keys of this character worn orloosened keyconnections can be reiitted and tightened, and when initially connectingkeyed partsthe very. cousiderable expense and time .usually requiredfor-accurate fitting and finishing-is obviated. lt .seems desirabletomake such oversized self-fitting keys about five one-thousandths orten one-thousandtlis of an inch larger in `each transverse directionwhere cutting action takes place thanr the standard size self fittingkeys of this character, so that badly .fitted or worn keyways` can. beeffectively taken careof'inthis way, and where a selffitting key hasbeenrepeatedlydriven out the parts may be tightlyfitted and'wedged apartby the useof such a special or. oversize l-rey. YVhere it isexpectedthat.suchself-fit-- ting keys `are to be removed. especially`where, such removal takes place at relatively. frequent interifalsit isquite desirable to heavily oil fn'grease the keys, especially attheirforward portions, before driving them, effective lubrication .preventingthe abrasionfor cutting action which otherwise. sometimes tends totakeplace Abetween the fiatk surfaces of the keyway and `thesideslof thekeyA back of. its cutting edgeswhere these faces are so strongly pressedtogether without.y lubrication.I lfihenzproperly lubricated', however,a.

suit-able selfritting key may bedriven. out

The key may as- .indicated be a-nd'replaced a number of times withordinary. care without undesirably loosening the connection.

Figs. 7 andi 8 show another illustrative forinof self-fitting key inwhich a wedging tapered'portion or face 42 is formed on one of thelongitudinalfaces of the key, prefer.- ably onzits outerface and thistapered portion may have the .usual` degree of taper of an eighthof aninchA per footfor relatively short hardened keys of this character, soas to` lit in the'keyyway which may be cut with al siniilarktaper. The.key. may be formed with one or Vmore lateral cutting edges49 a1id,.ifydesired, a reduced forward aligningr or guiding portion 44 may be formedso as to provide a. guiding` face or Vmember ahead of yeach of thesecutting edges 49,. and formed with lateral and vtopcutting edges 45.-,46,@ if desired. v Vith this arrangement wluneftliev wedging upper`surface 42 of the key isfcarriedidowntoyor adjacent the cuttingfedges 49it is `naturally somewhat narrowen than these cutting edges 49 or therearwardly extending lateral faces `of the key body 4l., For vthisreasonthe tapered face between its edges 43rproperly engages andcooperates with the.I tapering keyway originally. formed in-the shaftand cooperating partivhich promotes the accuracy of lit between. theseparts. v

Figs. 9l and 1,0 show another illustrative form of key inwhich thecutting edges are formed with a. cutting angle ofy about 90o which'`cuts fairly well, although` not quite as easily in such materials, as acutting angle of about 750 illustrated in connection. with thev otherfigures. This key. 51 may have the lateral cuttingedgesand the uppercutting edge 52 of such character and where av forward aligning guidingportion.

edges whichmay thus be located'at .the same.

longitudinal point on the key.- If desired, similarsquare or 90@cuttingedges such as 56 may be formed on the forwardvaligning guidingportion of thekeyto take careof any projectionsl or irregular portionsofthe ykey-way.v As indicatedin Fig, 9, the cut-ting headfoffthis keymaybe. suitably hardened while the other. or rear driving end' ofthe keymay be left.: in soft or annealed condition sothat more or less off thisend caribe cut..off. by. hack saw-s or otherwise'removed beforey the keyisl driven into a keyway as in-tliecase of"theFigrgxl 5-key. Fig.l 10also illustrates the use of' slightly rounded or beveled corners orlongitudinal edges 58 on these keys which are sonietin'ies desirable toprevent the workmen cutting themselves on the sharply ground edges whichare naturally formed in finishing the keys and also to reduce theundersirable cutting action' on the metal which sometimes occurs withsuch sharp edges. These self-fitting keys have proved Very successfulunder service condit-ions and careful tests made with such keys ascompared with the ordinary keys which vhave been hand fitted withunusual care show that the self-fitting key allows considerably lessyield between the 4parts under similar loads or forces so that a muchgreater degree'of rigidity and strength of driving connection is thus`secured while` the long and expensive hand fitting of the usual keys iscompletely eliminated.

This invention has been described in connection with a number ofillustrative eml'aodimentsa forms, proportions,y orders of steps,arrangements, sizes and materials, to the details of which disclosurethe invention is not of course to be limited since what is claimed asnew and what is desired to be secured by 'Letters Patent is set forth inthe appended claims.

kl. The process of fitting driving keys in the rough keyways of shaftsand cooperating parts, which comprises driving into such 'a keywvay arectangular sectioned key and simultaneously sizing or fitting at leasttwo rectangularly located inner surfaces of the keyway and tightlyforcing and wedging into the sized keyway the adjacent body portion ofthe key. j

2. rlhe process ofr fitting driving keys in the keyways of shafts andcooperating parts, which comprises driving into such a keyway arectangular sectioned key and simultaneously sizing at least tworectangularly located inner surfaces of the keyway and tightly forcinginto the sized keyway the body portion of the key.

3. The process of fitting drivii'ig keys' in the rough keyways of shaftsand cooperating parts, which comprises driving into such a keyway arectangular sectioned key and simultaneously sizing or fii'iishing atleast several of the inner surfaces of the keyway by cutting portions:formed adjacent the forward'end of the key and forcing and wedgng intothe sized keyway the :.zdjacent body portions of the key.

Il. The process of fitting driving keys in the i krough keyways ofshafts and cooperating parts, which comprises driving'into sucha keywaya` rectangular sectioned key and s1- multaneously sizing or finishing atleast one yof the inner surfaces of the keyway by a cutting portionformed adjacent the forward end of the key and forcing and wedging intothe sized keyway the adjacent body portions of the key.

The process of fitting driving keys in the rough keyways of shafts andcooperating parts, which comprises driving into such a keyway arectangular sectioned key and simultaneously sizing or fitting thekeyway, forcing into the sized keyway the adjacent body portion of thekey and also inremoving undesirable parts of the rear end of the key toadj ust its effective length. l

'6. The process of fitting driving keys in the rough keyways of shaftsandcooperating parts, which comprises driving into such a keyway arectangular sectioned key and simultaneously sizing or fitting at leasttwo rectangularly located inner surfaces of the keyway and tightlyforcing into the sized mywayfthe bodyportion of the key and also inremoving undesirable parts ofthe rear end of the rkey to adjust itseffective length.

Y. T he process of fitting driving keys in the rough keyways of shaftsand cooperating` parts, which comprises driving into such a keyway arectangular sectioned key and simltaneously sizing or fitting at leasttwo inner surfaces of the keyway and tightly forcing into the sizedkeyway the body'portion of the key and also in removing undesirableparts of the rearend of the key to adjust its length.

8. The process of fitting keys in the keyways of shafts andcooperatingpart's, which comprises driving into such a keyvvay arectangular sectioned key and simultaneously sizing at least tworectangularly located inner surfaces of the keyway and tightly forcinginto the finished keyway the body portion of the key.

The process of fitting driving keys in the rough keyways of shafts andcooperating parts, which comprises driving into such a keyway arectangular sectioned key and simultaneously sizing or finishing atleast several of the inner surfaces of the keyway by cutting portionsformed adjacent the forward end of the key and forcing or wedging intothe finished keyway the adjacent body portions of the key having atleast as great width as such adjacent cutting portions.

10. The process of fitting driving keys in the rough keyways of shaftsand cooperating parts, which comprises driving into such a keyway a.rectangular,sectioned key and sinultaneously sizing or finishing atleast several of the inner surfaces of the keyway and forcing into therfinished keyway the adjacent body portions of the key to tightly conneetthe cooperating parts.

11. The process of fitting driving keys in the rough keyways of shaftsand cooperating parts, which comprises driving into such a keyway arectangular sectioned key and simultaneously cutting and finishing` atleast one of the driving faces of the keyway by a plurality ofsuccessively acting cutting edges formed on the forvvardypart ofthefkeyand simultaneously keepmgthe front part 'ofthe key 'in alignmentandtrghtly forcing or Wedging the body lofthe key into the f'mishedkeyvvay totigh'tly co'imect thecooperiinished keyivay totightly connectthe cooperating parts.

1S. The process of fitting ykeys in the rough keyways of shafts andcooperating parts, which comprises driving into such a keyway apolygonal Asectioned key and simultaneously cutting and sizing at least`one of the faces of the key'way by a cutting edge formed on theforwardpart of the key and tightly forcing thebody of the key into thefinished keyvvayito tightly connectthe cooperating parts.

14. The process'offitting driving keys vin the keyways of shafts andcooperatingparts', which comprises driving into such a keyway aJrectangular sectioned key and simultaneously sizing the vkeyway and'forcing or Wedging into the sized Akeywaythe body ,portions of the keyto tightly connect'the cooperating parts.

15. The process of fitting driving'jkeys in the rough keyWays offshaftsand cooperating parts Whichcomprises driving into such a keyWayarectangular 'sectioned key having an oiled cutting head andsimultaneously cuttingv and' sizing atleast one of the faces of thekeyWay and-tightly forcing and wedging thebody of`the'key into thefinished keyway to tightly connect the cooperatino parts and drivingthelkey out of the keyway when they parts'are to be'. disconnected.

16. The process oflitting driving keysl in the rough keyways of shaftsand cooperating parts Which comprises driving into such a keyWay alubricated rectangular sectioned key and simultaneously cutting andsizing at least one of the faces of the key- Way and tightly forcing thebody of the key into the nished keyway to connect the cooperating parts.

17. In self-fitting drivingkeys, a key having a hardened cutting headcomprising on at least one of its tWo opposite driving faces and on itsouter intermediate longitudinal face a front aligning guiding member anda. cooperating rearwardly located main cut-y ting edge projectingoutward further than said guiding member to AWedge said key as itisdriven longitudinally into the keyway.

18. In self-fitting keys, a key having a cutting head comprising aWedging cutting` edge'to Wedge said key as it is d 1iven longitudinallyintothe keyway 19; ln self-fitting drivingkeys, a key having a `hardenedcutting hea d and arelatively soft driving end adaptedto be 'out on' 'toshorten the flength of the key,said cutting headcomprising a cuttingedge on atleast one of itstWo opposite driving faces and on anintermediate longitudinal face.

, 20. ln self-litting dri y'ing keys, a key having a hardened cuttinghead and a'relatively soft drivingend adapted to be cut off to shortenthe ylength of the key,vsaid cutting head comprisinga cutting edge.

21. In self-fitting driving'keys, a key havink' a hardened cutting headand a relatively soft driving end adapted to be cut offto shorten thelength of the key, said cutting head con'iprising acutting edge onatleast one of itstvo'opposite driving ifaces. n

' 22.1` ln self-iitting keys, a key having a cutting head comprising ahard cutting edge und a relatively soft driving end.

23. In self-fitting driving keys, a rectangula-r sectioned key having oneach of its two opposite driving faces and on at least the outerintermediate longitudinal facea rcutting edge and a front guidingaligning member `projecting outward 'less than said cutting edge and achip retainer recess between each of said cutting edges andthelcooperating guiding members.

24;. lin self-iittlng driving keys, a rectanguiar sectioned keyhaving oneach of yits two opposite drivingfaces and on at least an intermediatelongitudinal face a cutting edge and a frontfguiding aligningmemberprojecting outward less than said cutting idinal face a ,cutting odge`and a chip re-y tainer recess adjacent each of said cutting edges.l n

26. ln self-fitting driving keys, a key having on at least one of itstivo opposite driving faces and on an intermediate longitudinal face acutting edge.

27. In self-fitting driving keys, a rectangular sectioned key having onits outer longitudinal face a cutting edge having a cutting angle ofabout 75o or more and an adj acent'chip recess and a cooperating cuttingedge on at least one of the lateral driving faces of the key.

28. In self-fitting keys, a key having a fiat side and havingon anopposing longiy lateral Wedging action toward said fiat side of the keysimultaneously With the cutting action of said cutting edge.

29. In self-fitting driving keys a rectan-y gular sectioned key havingon a longitudinal face a cutting edge having such a large cutting angleas to produce a lateral Wedging action simultaneously with the cuttingaction of said cutting edge. n

30. In self-ttingdrivingkeys, a key having a plurality of cutting edgeson each one of several of its adjacent faces and having a front guidingaligning member projecting outward less than said cutting edges and achip retainer recess between said guiding member and said cutting edges.

31. In self-fitting keys, a rectangular sectioned key having a cuttingedge on each one of several of its adjacent faces and having a forwardlyextending front guiding member.

32. In self-fitting keys, a rectangular sectioned key having a cuttingedge on each one of several of its adjacent faces.

33. In self-fitting driving keys, a rectangular sectioned key having oneach one of several of its adjacent faces a cutting edge and an adjacentchip retainer recess.

34. In self-fitting driving keys, a rectangular sectioned key ofhardened steel having on each of its opposite driving faces a pluralityof cutting edges of progressively increasing Width to produce a fit asthe key is driven or forced into a rough iinished key- Way.

35. In self-fitting driving keys, a key having on one of its faces aplurality of cutting edges at progressively increasing distances fromthe opposing face. v

36. In self-fitting driving keys, a vsubstantially rectangular sectionedkey formed on several of its faces with a pluralityof successivelyacting hardened cutting edges and with a chip retainer recess betweensaid cutting edges.

37. In selfditting driving keys, a sub-A stantially rectangularsectioned key formed.

on one of its faces' with a plurality of cutbetween said Acutting edges.

38. In self-fitting drivingv keys, a key formed with a plurality ofsuccessivelyv acting hardened cuttingedges and with a chip retainerrecess between said cutting edges.

39. In self-fitting keys, a substantially rectangular sectioned keyformed on its opposing driving faces Witli a hardened cutting edge toresize the keyway as the key is forced into the same.

40. In self-fitting driving keys, a subst-an tially rectangularsectioned key comprising a cutting edge formed on one of its faces tosize the corresponding side of the keyivay the key is forced into thesame.

Lil. In self-fitting ydriifv'ing keys, a key having on each of its twoopposite driving faces a cutting` edge and a front guiding ,aligningmember projecting outvv rd less than said cutting edge and a chipretainer recess between said guiding member and said cutting edge.

42. In selftting driving keys, a key having on one of its faces acutting edge and a front guiding aligning member projecting outward lessthan said cutting edge and a chip retainer recess between said guidingmember and said cutting edge.

43'. In self-htting driving keys, a key liar'- ing on one of its faces acutting edge and a front guiding member in front of and projecting`outward less thanv said cutting edge. l y

4d. In self-fitting keys, a key having on one of its faces a cuttingedge and a front guiding member.

45. In self-fitting keys, a rectangular sectioned key having on eachvoneof several of its faces a cutting edge and a'forivardly extending frontguiding member.

4G. In self-fitting keys, a rectangular sectioned key having on one ofits faces a cutting edge and an adjacent chip retainer recess.

47. In self-fitting keys, a substantially rectangular sectioned keycomprising a cutting edge formed on one of its facesvto produce a tighttit as the keyis forced into the keyvvay. y

